Pressure regulator

ABSTRACT

A pressure regulator has a closing member ( 4 ) which controls a pressure-medium inlet ( 2 ) and on which is supported a valve spring ( 7 ) arranged in a spring can ( 8 ). The spring can ( 8 ) consists of a casing part ( 9 ) and of a lid ( 10 ). The valve spring ( 7 ) is supported with one end against this lid ( 10 ). Said lid is pushed into the casing part ( 9 ) until the necessary spring force is set exactly and is then connected to the casing surface ( 15 ) of the casing part ( 9 ) by means of radial indentations ( 12, 13 ).

[0001] The invention relates to a pressure regulator with a closing member, on which is supported a valve spring which bears with its other end against an upper end face of a spring can, said closing member having means for calibrating the tensioning force of the valve spring, in particular for fuel injection into an intake system of a motor vehicle.

[0002] Pressure regulators of the abovementioned type are installed, for example, in present-day motor vehicles and are generally known. For many applications, it is necessary that the opening force of the closing member of the pressure regulator and therefore the pressure regulated by the latter are always as exact as possible in spite of unavoidable manufacturing tolerances. This purpose is served, at the end of manufacture, by a calibrating operation. In this, a check is made as to the pressure at which the pressure regulator opens, and then, in order to set the pressure point, the end face of the spring can is pressed to a greater or lesser extent into the spring can, so that the valve spring is tensioned to a greater or lesser extent.

[0003] It has been shown, however, that such regulators can be calibrated only in a complicated way and with relatively high inaccuracies. The reason for this is, primarily, that the spring can pressed in on the end face, after being pressed in, inevitably springs back by an amount resulting from material elasticities. It is therefore necessary, during the pressing-in operation, to overrun the calibrating point somewhat and hope that, after the springback, the correct opening pressure is obtained. It is not possible, in this case, to avoid a situation where the pressed-in portion occasionally springs back less than expected and too high an opening pressure is therefore set. Such a fault can no longer be rectified subsequently by recalibration.

[0004] The problem on which the invention is based is to design a pressure regulator of the type mentioned in the introduction, in such a way that it is possible to carry out calibration which is as accurate as possible.

[0005] This problem is solved, according to the invention, in that the spring can consists of a casing part and of a lid, and in that the lid is connected to the casing surface of the casing part in a position fixing a desired spring force.

[0006] By virtue of this configuration, during the calibrating operation, the lid can be displaced axially relative to the casing part until the desired spring force is set, the lid only then being connected to the casing part. Since this connection is made on the casing surface of the casing part, there is no fear that the lid will spring back, so that the spring force can be set very accurately.

[0007] The lid could be designed as a component to be slipped over the casing part or as a component bridging the casing part. It is configured in a particularly simple way if it is pushed into the casing part and comes to bear with a flanged edge against the casing surface on the inside.

[0008] The lid can be connected to the casing part in very different ways, for example by means of screws or rivets leading radially into the casing part or by welding, soldering or adhesive bonding. A very simple connection is obtained when, according to another development of the invention, the casing surface of the casing part has indentations engaging into the edge of the lid.

[0009] The lid can be connected to the casing part particularly accurately in the position found during calibration, when the indentations are individual tabs which are formed by U-shaped incisions into the casing surface and by pressing the material delimited by the incisions into the edge of the lid.

[0010] Alternatively, however, it is also possible for the indentations to be formed by protuberances in the form of a spherical cap, the protuberances of the casing surface of the casing part and of the edge engaging into each other.

[0011] The invention permits various embodiments. In order to make its basic principle even clearer, one of these and a modified detail are illustrated in the drawing and are described below. In the drawing:

[0012]FIG. 1 shows a longitudinal section through a pressure regulator according to the invention,

[0013]FIG. 2 shows a longitudinal section on an enlarged scale through the connection region between a casing part and a lid of the pressure regulator,

[0014]FIG. 3 shows a side view of the region according to FIG. 2,

[0015]FIG. 4 shows a longitudinal section on an enlarged scale through a connection region modified in relation to FIG. 2.

[0016] The pressure regulator shown in FIG. 1 has a housing 1 with a pressure-medium inlet 2 and a plurality of pressure-medium outlets 3, 3′. Above the pressure-medium inlet 2 is arranged a closing member 4 which blocks this pressure-medium inlet 2 below a fixed pressure.

[0017] The closing member 4 is held by a diaphragm 5 which closes off a pressure space 6 upwardly. This closing member 4 is prestressed in the closing direction with an exactly defined force by a valve spring 7. The valve spring 7 is itself arranged in a spring can 8 which is connected to the housing 1 and which consists of a casing part 9 and of a lid 10. The lid 10 has an upwardly directed edge 11 which bears against the inner casing surface 15 of the casing part 9 and which is connected to the casing surface 15 of the casing part 9 by means of a plurality of indentations 12, 13 distributed over the circumference of the casing part. Furthermore, the lid 10 has an inner end face 14, against which the valve spring 7 bears.

[0018]FIGS. 2 and 3 illustrate that the indentations 12, 13 each have a tab 16 which engages from the casing part 9 into the edge 11 of the lid 10. For this purpose, the casing part 9 receives in each case a U-shaped incision 17, as shown in FIG. 3. The tabs 16 can be pressed in by means of the same tool with which the incisions 17 are also formed. Such a tool presses, at the same time as the tab 16, a corresponding tab 18 of the edge 11 inwards.

[0019]FIG. 4 shows that the indentations 12 and 13 may also be formed by protuberances 19, 20 of the lid 10 and of the wall of the casing part 9 which are in the form of a spherical cap and engage one into the other. 

Patent claims
 1. Pressure regulator with a closing member, on which is supported a valve spring which bears with its other end against an upper end face of a spring can, said closing member having means for calibrating the tensioning force of the valve spring, in particular for fuel injection into an intake system of a motor vehicle, characterized in that the spring can (8) consists of a casing part (9) and of a lid (10), and in that the lid (10) is connected to the casing surface (15) of the casing part (9) in a position fixing a desired spring force.
 2. Pressure regulator according to claim 1, characterized in that the lid (10) is pushed into the casing part (9) and comes to bear with a flanged edge (11) against the casing surface (15) on the inside.
 3. Pressure regulator according to claim 2, characterized in that the casing surface (15) of the casing part (9) has indentations (12, 13) engaging into the edge (11) of the lid (10).
 4. Pressure regulator according to claim 3, characterized in that the indentations (12, 13) have individual tabs (16) which are formed by U-shaped incisions (17) into the casing surface (15) and by pressing the material delimited by the incisions (17) into the edge (11) of the lid (10).
 5. Pressure regulator according to claim 3, characterized in that the indentations (12) are formed by protuberances (19, 20) in the form of a spherical cap, the protuberances (19) of the casing surface (15) of the casing part (9) and of the edge (11) engaging into each other. 